Weaving shuttle



March 25, 1969 A. FREIHOFER wmvms SHUTTLE Sheet ot2 Filed Nov. 17, 1966March 25, 1969 A. FREIHOFER WEAVING SHUTTLE Sheet Filed Nov. 17. 1966 xFig.3

Fig.6 E

3,434,507 WEAVING SHUTTLE Alexis Freihofer, Tann-Ruti, Zurich,Switzerland, assignor to Ruti Machinery Works Ltd., formerly CasperHonegger, Switzerland, Ruti, Zurich, Switzerland Filed Nov. 17, 1966,Ser. No. 595,128 Claims priority, application Switzerland, Dec. 23,1965, 17,740/65 Int. Cl. D03d 47/14 US. Cl. 139-125 12 Claims ABSTRACTOF THE DISCLGSURE A shuttle for a weaving loom having a retainingarrangement which holds a weft yarn with a predetermined force forpicking the yarn into the shed of the loom and from which the yarn canbe drawn out after the pick has been completed. The retainingarrangement comprises at least two separate retaining means whichprovide different degrees of retaining force for holding the yarn andwhich are independently adjustable so that the retaining force providedby each can be individually varied to reliably retain the yarn duringmovement through the loom and to allow the yarn to be drawn out of theshuttle by a braking force without excessive springing back of the yarn.

The present invention relates to a shuttle for a weaving loom and inparticular to a weft yarn picking shuttle having a retaining arrangementin which weft yarns are retained with a predetermined force to introducethem into the shed, and from which the weft yarns can be withdrawn afterthe pick has been completed.

A weaving shuttle is already known which has two clips for retaining theweft yarn and for introducing the yarn into the shed from one directionand then from the other. During this procedure, the yarn is drawn offdirectly from a large supply bobbin disposed externally of the loom. Theshuttle has a clip at each end, one clip serving for picking in the onedirection and the other for picking in the other direction. Each cliphas a fixed part against which a plate rotatable about a pivot ispressed. The yarn is jammed between the fixed part and the plate.

Furthermore, a shuttle is also known which contains a yarn retainingarrangement having a braking element consisting of a multiplicity ofbristles impinging and bearing against a plane.

When a shuttle of the type described or another picking member such as,for example, a rod provided with a yarn retaining arrangement, is usedin a weaving process in which the yarn is, after the pick has beencompleted, drawn out of the retaining arrangement, then the pickingmember is required on the one hand to retain the yarn reliably andsecurely and on the other hand sufliciently loose to ensure that at theinstant at which the yarn leaves the retaining arrangement it will not(or will not to any great extent) spring back due to its elasticity.Excessively vigorous springing-back is detrimental to reliable graspingof the yarn in order to stretch it before being beaten up by the sley.Consequently, the quality of the resulting fabric is diminished. Firmretaining of the yarn by the shuttle to prevent slipping of the yarn isparticularly important when the length of the yarn to be picked isdetermined by the fact that the shuttle carries the yarn with a free endof pre-determined length. During the picking step and, at apre-determined position of the shuttle during movement along the shed,the yarn to be picked is stopped on the side of the large-supply bobbinand is thus drawn out of the retaining arrangement.

The known shuttles mentioned heretofore do not satisfactorily fulfillthe above-mentioned requirements, i.e., they either retain the yarn sofirmly that it cannot be ice drawn out of the travelling shuttle withoutspringing back by an excessive amount, or they retain it so loosely thatit slips in the retaining arrangement and accurate supplying of therequired length is not possible.

Advantageously, these problems are avoided by the shuttle or pickingmember of the present invention. In general, the present invention isdirected to a shuttle which will ensure uniformity in the introductionof yarn into the shed. This uniformity requires reliable retaining ofthe weft yarn in the shuttle and also a form of yarn withdrawal which isnot or is only very slightly jerky at the instant the yarn is drawn outof the shuttle.

The present invention thus contemplates a shuttle or picking memberhaving a retaining arrangement with at least two retaining means orzones of varying retaining force, the first zone exhibiting the greaterdegree of retaining force and, as seen in the direction of the yarnmovement during the withdrawal of the yarn from the retainingarrangement, being located in front of the second zone, which exhibitsthe smaller degree of retaining force.

In a particularly advantageous process for transferring yarn to theshuttle, the yarn is laid as a loop through the shuttle and then theloop is drawn out. However, in order to achieve the advantages of thisinvention and particularly to provide uniform yarn insertion, in such aprocess, entanglement of the yarn as it is transferred to theyarnretaining arrangement must be avoided. In accordance with thisinvention this is achieved by a special construction of the shuttlewhich is so shaped that the two halves of the loop are kept separatefrom each other, during the process.

The invention will now be described in greater detail in the descriptionof several embodiments and with reference to the accompanying drawingsin which:

FIGURE 1 is a plan view of one embodiment of the shuttle or pickingmember of this invention;

FIGURE 2 shows an elevation of the shuttle shown in FIGURE 1, partly insectional along line 11-11;

FIGURE 3 shows an elevation of another embodiment of the invention;

FIGURES 4 and 5 show plan views of two additional embodiments of theinvention which operate in a similar manner; and

FIGURE 6 shows still another embodiment in elevation.

In the figures, the same reference numerals designate like parts.

The shuttle shown in plan view in FIGURE 1 is designated by thereference numeral 11. The shuttle 11 has an elongated body withapertures 12 and 13 at each end. These apertures, as shown in thedrawings, extend completely through the shuttle in the horizontaldirection. Towards the center of the shuttle, each aperture narrows toform a slot 14 or '15, respectively. Each of the slots leads to aretaining arrangement, one of which comprises a first braking plate 16that presses against a cover plate 17 serving as an abutment and thattogether with the plate v16 constitutes a first retaining means or zone,and a second similar braking plate 18 that also presses against thecover plate 17, again acting as an abutment. In this manner, the plate18 and the cover plate 17 form a second retaining means or zone of thearrangement. The plate 18 is not shown in FIGURE 2 due to the selectedposition of the sectional view along which this figure is taken.

The cover plate 17 has not been shown in FIGURE 1 in order that thebraking plates, 16, 18, 19 and 20 may be visible. Plate 17 should beconsidered as having been removed from the shuttle shown in FIGURE 1.

correspondingly, there is a second retaining arrangement at the otherend of the shuttle. This arrangement comprises a braking plate 19 whichis adapted to be pressed upwardly in a first retaining means or zone andalso a second braking plate adapted to be pressed upwardly in a secondretaining means or zone. Both plates also press against the cover plate17 that acts as an abutment. In FIGURE 2, plate 19 is not shown. Theplates or elements 16, 18, 19, 20 are of elongated shape and are roundedat their ends. They are, as can be seen from FIGURE 2, bevelled awayfrom the plate 17 at the forward end as seen in the direction ofpicking.

The plate 16 is upwardly biased or pre-tensioned by means of the screw21 and the spring 22, i.e., it is pressed against the cover plate 17with a predetermined force. Similarly the plate 20 is biased against thecover plate 17 by means of the screw 23 and the spring 24. The screws 21and 23 permit the adjustment of the pressure which the plates 16 and 20,respectively, exert against the cover plate 17. The biasing of theplates 18 and 19 is exactly the same as described for plates 16 and 20.

In order to achieve exact positioning of the yarn 25 under the brakingplate 16 (i.e., between the braking plate and the cover plate), theguide or positioning pins 26 are provided. A yarn introduced between theplates 16, .17 is by this means retained exactly in the positiondetermined by the pins 26, as shown in FIGURE 1. Appropriate pins orpegs 27 are also provided on both sides of the plate 19.

The hook secured on the loom is movably arranged, so that it is able tomove from the position shown in FIGURE 1 through the aperture 12. Duringthis movement, it engages yarn stretched on the other side of theshuttle 11 between the nozzle 34 and the yarn guide 28 and draws it, asa loop, through the aperture v12. At the same time, the two loop halves25 and 25" are formed. The loop half 25 is up further than the loop half25", i.e., it is raised higher than the other loop half as shown inFIGURE 2.

The free end 32 of the yarn 25 is retained by a suction nozzle 34. Theyarn travels from the yarn guide 28 over a yarn clip or brake 31 securedto the loom to a yarn supply means located at the side of the loom andnot shown.

During operation, before the propulsion of the shuttle 11 towards theleft (as viewed in FIGURES 1 and 2) the hook '30 engages the yarn 25supplied to it. by the yarn guide 28 and draws it through the aperture12 in the shuttle 11. At this instant, the yarn clip 3.1 is stillclosed. The hook 30 then remains in the position shown in FIGURE 1.Subsequently, during the propulsion of the shuttle 11, the slot 14(which is at the level of the loop half 25'), engages the loop half 25'.During the drawing out of the yarn 25 from the suction nozzle 34, theloop half 25' passes into abutment with the two pins 26 and the loophalf 25" into abutment with the curvature located under the projection33. Since, at that instant, the yarn clip 31 has trapped the yarn 25,the yarn, which has a free end 32, is drawn out over the hook 30. Afterthe shuttle .11 has moved towards the left through a predetermineddistance, the clip 31 is opened and the yarn 25 is drawn through theshed while simultaneously being drawn-off from a large-supply bobbin. Asthis takes place, the position of the yarn in the shuttle is thatdesignated by the reference numerals 25a and 32a in FIGURE 1.

Shortly before the shuttle (during its travel towards the left) leavesthe shed at the left-hand end of its path, the clip 31 is closed again.Consequently, the yarn 25 is completely drawn out of the shuttle 11. Theinstant when the yarn is clamped by the clip is so selected that thefree end 32 (32a) of the picked weft yarn projects out of the loom by ashort, predetermined amount. The retaining means of the retainingarrangement formed by the plate 16 and plate 17 is therefore required toretain the yarn 25 firmly enough to ensure that the yarn, duringintroduction into the shed and particularly from that instant at whichthe brake 3.1 is opened, does not slip therein. On the other hand, thebraking elfect of the retaining arrangement must not be so great thatthe yarn springs back a noticeable extent as it leaves the arrangement,i.e., the end of the yarn does not snap back toward the shed. The yarnend 32 leaving the shuttle must, as the instant it leaves the retainingarrangement formed by plates 16, 17, and 18, be taken over by a holdingmeans formed, for example, by a suction nozzle. This holding means isrequired to hold the yarn introduced into the shed stretched before andwhile it is beaten up by the sley.

In order to prevent springing-back of the yarn, the pressure applied byplate 16 is made sufiiciently strong to ensure secure and reliableretaining of the yarn 25. As can be seen from FIGURES 1 and 2, thebraking plate 18 is also arranged in the direction of the yarn movementtaking place during the drawing-out of the yarh from the retainingarrangement. Plate 18 is biased against the cover plate 17 by a pressurewhich is smaller compared with the pressure of the plate 16. Thissmaller pressure is so selected that the pull on the yarn 25 as itslides out through the plate 18, produces at most a practicallyinsignificant springing-back of the yarn 25.

In order to achieve uniformly in the supply of the desired length of theyarn 25, i.e., in order to exactly dimension the length of the yarn 25picked into the shed, it is essential that the free yarn end 32a shouldalways have the same length. Thus, it must never happen that the twoyarn halves 25 and 25" become entangled with each other. In order toprevent such entanglement, a projection 33 is provided in the shuttle 11on the underside of the slot 14. As shown in FIGURE 2, the projectionextends into the aperture 12. With this construction, the lower loophalf '25", during the propulsion of the shuttle, takes up its positionin the curvature located under the projection 33. It will also beappreciated that care'must be taken to ensure that the free end 3211 ofthe arm 25a does not become entangled or jammed-in, during the travel ofthe shuttle, with any part of the reed or with any other part of theloom. In order to prevent this from happening, there is provided on therear side of the shuttle (as viewed in FIGURE 2), at the level of theslot 14, a horizontal notch for receiving the free yarn end 32a duringthe travel of the shuttle. The length of the said notch is as long as orslightly longer than the yarn portion extending from the outerpositioning pin 26 as far as the free end 32a.

Since the arrangement and mode of operation of the retaining arrangementformed by the plates 19 and 20 together with the plate 17 is the same asthat of the retaining arrangement described in the foregoing text andoperates accordingly during the travel of the shuttle 11 from the lefttowards the right, no further description thereof will be given.

Two materials have primarily been found to be advantageously used forthe plates 16, 18, 19 and 20. One of these materials is wood and theother is a plastic material coated with a layer of chromium.

In the case of the embodiment illustrated in FIGURES 1 and 2, the coverplate consists of a plastic material and the plates 16 and 17 or 19 and20 are made of wood. Under these circumstances, a compression force onplates 16 and 19 of 50 to grams and on plates 18 and 20 of 5 to 30 gramshas been found to be advantageous.

In addition, the guiding of the plates 16, 18, 19 and 20 during theirupward and downward movement is advantageously such that the surface ofeach of the plates, which is able to contact the cover plate 17, remainsparallel to itself. However, a slight degree of deviation from amovement of this kind is also possible without involving any danger ofunsatisfactory operation.

As heretofore noted, FIGURES 3 through 6 show further embodiments of aretaining arrangement suitable for purposes of this invention. Only onehalf of a shuttle 11 is shown in these figures. In the shuttle shown inFIG- URE 3 an aperture 13 is also provided for the drawing-in of a weftyarn. In place of a weaker, spring-biased plate 18 of the secondretaining means or zone of the retaining arrangement, a carrier 40having bristles 41 on its upper side is provided. The carrier 40 is, inthis embodiment, not movable. Due to their elasticity, the bristlespress against the cover plate 17. By selecting a suitable bristlematerial, the force by which the yarn is retained is brought to oradjusted to the desired degree in a yarn brake or retaining means ofthis type. In place of bristles, it is also possible to use a fur-likematerial, a plush-like material, or a like fibrous material.

In the embodiment shown in FIGURE 4, the retaining arrangement comprisesthree different retaining means or zones. Proper retaining of the weftyarn 25a is effected by means of the plate 42 and positioning of theyarn 25a on the plate is again achieved by means of the pins 26. As seenin the direction of movement of the yarn 25, during drawing from theretaining arrangement, there are additionally arranged plates 43 and 44which form two further retaining means or zones. The pre-tensioning ofthese plates diminishes step-wise, in the arrangement illustrated, fromthe plate 42 to the plate 44. In this arrangement, plate 44 is adaptedto be very weakly pretensioned so that the springing-back of the yarn isgreatly diminished. The pre-tensioning of the plates may, as shown inFIGURE 2, also again be effected by means of springs exerting pressurefrom below.

The embodiment in FIGURE 5 shows a further modification of theembodiment shown in FIGURE 4. Ac cording to FIGURE 5, there are providedin the shuttle 11 a first retaining means or Zone having the plate 50and the positioning pins 26, and also a multiplicity (in this case,four) of additional zones. The additional zones are for-med by theplates 52 to 55 which are biased or pre-tensioned from below, forexample, by means of a spring, and which impinge against an abutmentprovided by a cover plate. Due to the provision of five different zonesby plates 50, 52, 53, 54 and 55 a decrease in the braking force on theyarn can be achieved in extremely small stages, down to, practically,the value zero.

An example of an embodiment producing a decrease in the retaining orbraking force of the yarn which does not take place step-wise but in acontinuous manner is shown in FIGURE 6. In this case, there is again anaperture 13 formed in the shuttle 11. Similarly, the shuttle again has acover plate 17 serving as an abutment. The retaining arrangement isformed by a U-shaped leaf spring 60 having legs of varying length. Theleaf spring is secured fast with the shuttle 11 by means of its shortleg and with the aid of a securing means 61. Simultaneously, the longleg bears against a cover plate 17. The application pressure of thisdevice is decreased continuously in the direction towards its free endand can be so adjustcd that the force at the free end of the long leg isdecreased to zero. In this manner, it will be appreciated that the longleg provides a plurality of retaining means or zones along its length.For the positioning of the yarn, positioning pins 62 may again beprovided. The curvature of the U-shaped leaf spring separates the upperand the lower halves 25' or 25", respectively of a drawn-in yarn loop(as shown in the embodiment of FIGURE 1). In order the lower loop 25"may not become caught up in the securing means 61 of the leaf spring,yarn guiding pins 63 are advantageously provided.

While the novel features of the invention have been shown and describedand are pointed out in the appended claims, it is to be understood thatvarious omissions, substitutions and changes in construction andarrangement of the features shown and described may be made by thoseskilled in the art without departing fro-m the spirit and scope of theinvention.

What is claimed is:

1. A shuttle for a weaving loom having an elongated body and a retainingarrangement which holds weft yarn with a predetermined force for pickingsaid yarn into the shed of the loom and from which said yarn can bedrawn out after the pick has been completed, said retaining arrangementcomprising at least two separate retaining means which provide differentdegrees of retaining force for holding the yarn, the first retainingmeans providing the greater retaining force and being arranged in frontof a second retaining means in the direction of yarn movement whichoccurs during drawing out of the yarn from said retaining arrangementand said second retaining means providing a smaller retaining force thanthat provided by said first retaining means, each of said retainingmeans being adjustable independently of the other to provide varyingdegrees of retaining force, and the retaining force provided by eachbeing individually varied to reliably retain the yarn during movementthrough the loom and to allow said yarn to be completely drawn out ofthe shuttle by application of a braking force to said yarn withoutexcessive springing back of the yarn.

2. The shuttle of claim 1 in which at least one of said retaining meanscomprises an abutment and a plate, said plate being pressed against saidabutment by a resilient member and being adapted to move towards andaway from said abutment, the force exerted by said resilient memberbeing a'djusta-ble.

3. The shuttle of claim 1 in which said elongated body has an apertureextending perpendicular to its longitudinal axis and to the direction ofmovement of the shuttle in the loom for allowing introduction of saidweft yarn thereto in the form of a loop and a slot extending from saidaperture in the direction opposite to that of the weft picking directionand leading to said retaining arrangement for guiding the yarn thereto,said slot having one boundary face from which a projection extends intosaid aperture and said projection being arranged between the slot andthe rear wall of the aperture whereby the two halves of the yarn loopare kept separate from each other during movement of said retainingarrangement.

'4. The shuttle of claim 1 in which the second retaining means comprisesan abutment and a fibrous material impinging against said abutment.

5. The shuttle of claim 1 in which the retaining force of each of saidretaining means is so selected that the first retaining means providessufiicient force to reliably hold said yarn and the other retainingmeans are arranged sequentially in the direction of the yarn movementduring the drawing-out of the yarn from the retaining arrangement, theretaining forces of each of said other retaining means decreasing inrelatively small stages down to a relatively very small value.

6. The shuttle of claim 1 in which said elongated body has a rear wallwhich slides along the sley during the picking movement, said rear wallhaving a notch formed therein at the level of the retaining arrangementfor receiving the free end portion of the weft yarn to be picked, andsaid notch being at least sufiiciently long to insure that substantiallythe entire free end portion of the yarn is received thereby.

7. The shuttle of claim 1 in which said retaining arrangement includes apair of yarn positioning elements, said element being operativelyassociated with said first retaining means to locate the weft yarn at apredetermined position.

8. The shuttle of claim 2 in which each of said retaining means has aplate which is pressed against an abutment by a resilient member, theplate of the first retaining means being pressed by a force of from 50to grams and the plate of the second retaining means being pressedagainst the abutment by a force of from 5 to 30 grams.

9. The shuttle of claim 2 in which the plates and the abutment are madeof chromium-plated plastic material.

10. The shuttle of claim 2 in which the plates and the abutment are madeof wood.

11. The shuttle of claim 2 in which the plate is of elongated shape, thelonigtudinal direction thereof extending parallel to the path ofmovement of the shuttle, said plate 7 r 8 being bevelled away from theabutment at its forward 2,946,353 7/1960 Dunham 139125 end in thepicking direction and said forward end being 3,163,184 12/1964 Cherpin139125 rounde b 3,174,514 3/1965 Schafler 139 125 12. The shuttle ofclaim 2 in which said a utment is formed by a plate inserted in a wallof the shuttle. FOREIGN PATENTS 223,951 3/ 1958 Australia.

References Cited 971,273 9/1964 Great Britain. UNITED STATES PATENTS 92/1953 Italy,

948,945 2/1910 Smith 139126 1,729,413 9/1929 Ashton 139125 10 JAMES KEECHI, Primary Examiner.

